Assessing the Effects of Agronomic Management Practices on Soybean (Glycine max L.) Post-Grain Harvest Residue Quality in the Lower Mississippi Delta

Livestock producers often resort to either baling or grazing of crop residues due to high hay prices and reduced supply of other forages and silage in the markets. Soil-water-crop management practices can affect residue nutrient qualities for its use as cattle feedstock. A two-year study (2018–2019) was conducted to investigate the effects of irrigation (AI, all row-irrigation; ARI, alternate row irrigation; and RF, rainfed) and planting pattern, PP (SR, single row; and TR, twin-row) on soybean (maturity group IV cv. 31RY45 Dyna-Gro) post-grain harvest residue quality such as crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), acid detergent lignin (ADL), net energy for maintenance (NEM), net energy for gain (NEG), net energy for lactation (NEL), total digestible nutrients (TDN), and relative feed value (RFV). Irrigation has a significant effect on CP, ADF, NDF, and TDN while PP affected only NDF. All the above parameters were significantly affected except NEM by the contrasting climate conditions, particularly during July through August coinciding with early crop reproductive stages and maturity. The RFV values ranged from 70.4 to 81.6 and this lower range was attributable to nutrient translocation to seeds and higher lignification during plant senescence towards the grain filling stage of the crop as good quality hay records over 120 RFV. These results indicate that both irrigation and weather during soybean seed development can alter post-grain harvest residue quality parameters, thereby playing critical roles in its RFV.

Sustainable Biowaste Management in Cereal Systems: A Review

Among the field crops, cereals being the staple food for humans and feed for cattle, occupy 50.8 per cent of the cultivated land and contribute 52.5 per cent of the body calories. Cereals are the good source of carbohydrate, minerals, and dietary fibre for humans and animals. With the ever growing human population the agricultural production and agri-wastes are increasing across the globe. In Asia, Africa and Latin America, near about 66, 21 and 13 per cent of total estimated 2,060 Tg of biomass are generated every year. Burning has been the cheapest, simplest, easiest and quickest way of eliminating bulky unwanted biomass in-situ before raising of the succeeding crop(s). Rice, wheat, sugarcane and maize constitute 24, 23, 5 and 48 per cent of the global burnt residues. Although killing of problematic weeds, insects, and pathogens, and addition of valuable plant nutrients are the very basic objectives of this anthropogenic post-harvest residue management strategy but it releases noxious gases into the atmosphere polluting air and contributing to the global warming. Shorter sowing windows very often compel the farmers to remove crop residues through burning, especially in absence of alternative options for its productive and profitable disposal. Rising labour cost and their seasonal scarcity sometimes also insist the farmers to burn crop residues. However, stringent punitive actions have yet failed to curb such open burning in many countries in absence of the farmers’ friendly and financially viable options of crop residue management. In this chapter, attempts have been made to elucidate various sustainable crop residue management strategies in cereal systems.

Additive predictions of aboveground stand biomass in commercial logs and harvest residues for rotation age Pinus radiata plantations in New South Wales, Australia

Two systems of additive equations were developed to predict aboveground stand level biomass in log products and harvest residue from routinely measured or predicted stand variables for Pinus radiata plantations in New South Wales, Australia. These plantations were managed under three thinning regimes or stand types before clear-felling at rotation age by cut-to-length harvesters to produce sawlogs and pulpwood. The residue material following a clear-fell operation mainly consisted of stumps, branches and treetops, short off-cut and waste sections due to stem deformity, defects, damage and breakage. One system of equations did not include dummy variables for stand types in the model specification and was intended for more general use in plantations where stand density management regimes were not the same as the stand types in our study. The other system that incorporated dummy variables was for stand type-specific applications. Both systems of equations were estimated using 61 plot-based estimates of biomass in commercial logs and residue components that were derived from systems of equations developed in situ for predicting the product and residue biomass of individual trees. To cater for all practical applications, two sets of parameters were estimated for each system of equations for predicting component and total aboveground stand biomass in fresh and dry weight respectively. The two sets of parameters for the system of equations without dummy variables were jointly estimated to improve statistical efficiency in parameter estimation. The predictive performances of the two systems of equations were benchmarked through a leave-one-plot-out cross validation procedure. They were generally superior to the performance of an alternative two-stage approach that combined an additive system for major components with an allocative system for sub-components. As using forest harvest residue biomass for bioenergy has increasingly become an integrated part of forestry, reliable estimates of product and residue biomass will assist harvest and management planning for clear-fell operations that integrate cut-to-length log production with residue harvesting.